Fischer-Tropsch Synthesis in the Presence of Solvent Using Novel Carbon-Oxide Composite Supported Cobalt and Iron Catalysts

摘要

Currently, industrial progress caused the mass consumption of resources. The reserves of carbon resources under the ground are decreasing and as a result, the drying up of carbon resources has begun. On the other hand, the use of carbon resources has caused the environmental pollution such as global warming. The exhaust of harmful matters affects human bodies badly. Therefore, Fischer-Tropsch synthesis (FTS) using synthesis gas produced by the gasification of biomass attracts much attention because the biomass is regarded as a carbon neutral renewable matter and the FTS produces completely sulfur-free fuels. Nowadays publications related to the FTS are more than hundred and not only academic community but also industrial world have noticed the importance of this technology because of the drastic increase in the price of crude oil and the increasing demand for the clean alternative fuels. In this method called gas to liquid (GTL), one of the key technologies is the development of catalysts. So far various heterogeneous transition metal catalysts such as Fe, Co, Ni and Ru have been developed for this reaction. It is well-known that among them, Co based catalysts are advantageous for the practical application due to the high activity and selectivity to long chain linear hydrocarbons, high resistance toward deactivation, and lower price than Ru. Generally Co and Fe catalysts are deposited on the supports with high surface area (e.g., SiO_2, Al_2O_3, TiO_2 and ZrO_2) in order to increase the number of active Co, Fe metal species and silica-supported cobalt is one of the promising catalysts. Further, due to the high resistance to attrition and the ability to stabilize small clusters, alumina is one of the attractive support materials for Co or Fe based FT catalysts. Although usual transition metal-supported catalysts are made by the impregnation method, the preparation of catalysts using sol-gel method has become one of promising methods.